Steady state and time-resolved IR spectroscopy of the native and unfolded states of bovine ubiquitin: Protein stability and temperature-jump kinetic measurements of protein folding at low pH

Abstract

Infrared spectroscopy has been used to characterise the folded and unfolded states of bovine ubiquitin (a small protein of 76 residues) under acidic conditions (pH ~ 1); fast time-resolved measurements of protein unfolding, initiated by a laser-induced temperature-jump of ~ 8 °C, shows rapid refolding and β-sheet secondary structure formation on a timescale of a few milliseconds.